Improvement in desulphurizing ores



UNITED STATES PATENT OFFICE.

JOHN FELT OSGOOD, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN D ES ULPHURIZING ORES.

Specification forming part of Letters Patent No. 101,651, dated April 5,1870.

To a, whom, it may concern:

Be it known that 1, JOHN FELT OSGOOD, of Boston, Massachusetts, haveinvented certain Improvements in the Method and Process ofDesulphurating Sulphuret Ores; and I do hereby declare that thefollowing is a full, clear, and exact description thereof.

I claim to have invented the application of nitrous and oxygen gases tosulphuret ores while in process of roasting in asuitable oven or furnacealso, the mixing of pulverized albite, labradorite, or other feldspathicmineral with the ore while in process of roasting, to aid in expellingthe sulphur. I find along muffle-furnace convenient for my purpose. By amuffle-furnace I mean a furnace in which the fuel and products of itscombustion do not come in contact with the ores or other article undertreatment. As a convenient method, I supply the gases from smallfurnaces or plain retorts at the end or side of the large furnace bygas-tubes leading to different parts of the oven or large furnace,controlling the gases by stop-cocks, as desired. To generate the gases,I adopt as a convenient method the following: I put into pots in thesmall furnace, or into the retorts, sulphuric acid and nitrate of soda,or their equivalents. The gases generated from these by application ofheat pass through the tubes and are discharged upon the roasting Themixing of albite, labradorite, or other feldspathic mineral with theground ore while roasting may be accomplished in various ways. If a longmuffle-furnace be used, the pulverized ore may be supplied at the end ofthe chamber or oven most distant from the fire, and fed along toward thefire end either by machinery or by hand, and the pulverized albite orother feldspathic mineral is added, through doors for the purpose in thechamber, in'proper charges, and combines, as I suppose, with the sulphurof the ore, and, as I know, materially aids in the process ofdesulphuration.

I find by experiment that either fiuorspar or the natural mineral calledmagnesite, used instead of the minerals named, in the same way,practically serves as a substitute for them.

Should the ore not be thoroughly desulphurated by the first operation,it may be passed rapidly through the same process a second time. I find,too, that chemical action is aided by steam from a jet, generated bymeans of steam-coil placed over or in the furnace-fire or within thechamber, and thrown into the chamber or oven upon the roasting JOHN FELTOSGOOD.

Witnesses:

HENRY F. FRENCH, J OHN H. LOCKEY.

